Concentration of kyanite



Patented Dec. 15,

UNITED STATES PATENT OFFICE Francis x."l'artaron, Mulberry, Fla, asslgnorto Phosphate Recovery Corporation, New York,

is. Y.,a corporation of Delaware No Drawing.

pplieaflon April 9, 1941,

Serial No. 387,667

Claims. (Cl- 209-168) The present invention relates to an improved froth flotation. I

In a co-pending patent application, assigned to the same assignee as the present application, by Nathan K. Karchmer and Charles E. Heinrichs, Serial No. 349,128, filed August 1,1940, there is described a process of concentrating kyanite from its ores, which is characterized by a first step of conditioning an aqueouspulp of the kyanite ore in a conditioner by adding to and admixing concurrently with the pulp a the kyanite ore with acid and then washing out.

the acidthe kyanite becomes much more amenable to flotation. After such pretreatment the kyanite may be successfully concentrated by the addition to the pulp of a fatty acid as the only higher fatty acid in process, but any other fatty acid having at, least twelve carbon atoms can be used. Caustic soda and a water-immiscible oil or a soluble fluoride flotation reagent, possibly with slight amounts of It is unnecessary to theorize about what the g pretreatment with acid does to the particles 'of the suite ore, but the fact is. that for some reason this acid pretreatment and subsequent washing out of the acid leaves the ore-particles in such condition that the kyanite particles may 4 be separated by flotation much more easily than is the case with ore which .has not been so treated. Concentrated sulfuric acid, in the quan- 't'ity hereinafter mentioned, has been found to be 'a satisfactory acid for use in the pre-treatment of the kyanite-ore. Hydrofluoric acid has also been found effective as the pr'e treatment agent.

. joleic acid, in the quantity"-hereinafter mentioned, has been found particularly useful as amay also be used in conjunction with the fatty acid, as is shown in the examples that follow.

Example 1.--In practicing the process and ob-' taining the excellent results hereinafter set forth, Baker Mountain kyanite ore was comminuted to suitable particle size which was mostly minus 35-mesh and was largely desiimed,

thecomminution being accomplished in stages so as to reduce-the slimes to a minimum. .The comminuted ore was then agitated in a pulp at approximately 70% solids with 3.68 lbs. per ton of ore of concentrated sulfuric acid (specific gravity 1.84) for about three minutes. After thus" being pre-treated with acid,'.the ore was washed substantially free of acid; and in a pulp at approximately 70% solids was conditioned with oleic acid (red oil) in the amount of 0.26 lb. per ton of ore and with a frother consisting of pine'tar oil (P. '1. 101) in the amount of 0.14 lb. per ton of ore. The ore thus conditioned was subjected to froth flotation in 'a froth flotation machine with the following results;

1 mm wen n? Quartz {3}? g 7 I. P"- PercealPcrcoliPauatPerem cent 00.0 sass 64.86 1.04 100.0 am 44.55 2.06 2.00 00.1 41.1 4.00 04.10 0.04 9.0

- From the above data,'it will be noted that from ore containing 33.89% kyanite there was obtained a kyanlte concentrate having a grade of 94.55% kyanite, with 90.1% "recovery of, the kyanite in the ore. It will also be noted that these excellent results we're-obtained by the use of only a small amount of fatty acid as the only flotation agent, and without any depressing agent. v Example 2.--A.North Carolina kyanite ore, crushed to 35 mesh anddeslimed, was agitated with 2.40 lbs. of 48% hydrofluoric acid. per ton of ore, for three minutes in a pulp of 63% solids, then washed with water to remove the acid, conthe carrying out of this ditioned at 63% solids with red oil, 2.24 lbs. and pinetar oil #101, 0.14 lb. perv ton of ore and subjected to flotation. The concentrate was retreated in the usual way without addition of re- The products resulting from'this and subsequent tests were subjected to a sink and float test, the amount of sink being a measure of the kyanite present in the sample.

. Example 3.Another sample of the same ore, crushed to 35 mesh and deslimed, was agitated at 63% solids with 4.03 lbs. of sulphuric acid per ton of ore, washed free of acid and conditioned 2 minutes in a pulp of 63% solids with:

Pounds per ton of ore NaOH 0.50 Fuel oil -1 [1.74 Red oil- 1 1.61

It was then subjected to flotation as in the previous example with the following result:

Product Weight Kyanitc 58E323 Per cent Per cent Per cent Feed 100. 100. 0 Gone. 42. 9 93. 9 66. 9 M1d l5. 7 80. 2 20. 9 Tail 41.4 17.7 12.2 Combined cone. and mid 58. 6 92.0 87.8

Example 4.Stil1 another sample of the same ore, crushed through 35 mesh and deslimed, was agitated with sulphuric acid, 4.05 lbs. per ton and 7 after washing out the acid, conditioned for 2 minutes at 63% solids with;

,uufl Pounds per ton of ore S dium fluoride 1.00 Red oil I 2.24 5 P. T. 101---- 0.14

The pulp was then subjected to flotation, the concentrate being retreated as before-with the following result:

Product Weight Sink 33g; 4

Per cent Per cent 100.0 Conc 44. 9 94. 7 72. 5 id 10.8 74.2 13.1 i1 44.3 12.3 13.8

' What is claimed is:

l. A process of concentrating kyanite from, its ores, which comprises comminu ing the ore to suitable particle size, pre-treat ng the com-' minuted ore b-y agitating it in a pulp containing sulfuric acid, washing the sulfuric acid away from the ore, agitating the thus acid-treated and washed ore in a pulp containing a. higher fatty 1 acid, and subjecting the thus conditioned pulp 0f kyanite ore to froth flotation to separate a concentrate of kyanite.

2. A process of concentrating kyanite from its ores, which comprises comminuting the ore to suitable particle size and desliming the same. pretreating the comminuted ore by agitating it in a pulp containing sulfuric acid. washing the acid away from the ore, agitating the thus acidtreated and washed ore in a pulp free from any depressing agent and containing oleic acid as the only flotation agent, and subjecting the thus conditioned kyanite ore to froth flotation to separate a concentrate-of kyanite.

3. The process of claim 1 in which an alkali and a water-immiscible oil are used in conjunction with the higher fatty acid.

4. The process of claim 1 in which caustic soda and fuel oil are used in conjunction with the fatty acid.

5. The, process of claim 1 in which sodium 7 fluoride is added to the pulpin addition to the fatty acid.

' FRANCIS X. TARTARON. 

